Experimental allergic encephalomyelitis (EAE) an autoimmune disease of the central nervous system and similar to human demyelinating disease multiple sclerosis (MS) can be suppressed clinically and histologically in Lewis rats injected with myelin basic protein (BP) complexed to purified lipopolysaccharides (LPS). Prevous work has shown that this suppression results in in-vitro generation of antigen specific suppressor T-cells in the lymph node cells of BP-LPS immunized animals. The immunologic mechanism for this suppression of EAE in the BP-LPS immunized animals will be defined and both humoral and cellular immune response to the two forms of antigenic stimulus, BP and BP-LPS will be characterized. The role of macrophages in the activation of suppressor T-cells and processing of antigens will be investigated in more detail. These studies will be extended to transfer of EAE using lymph node, spleen and peripheral blood lymphocytes from BP and BP-LPS immunized animals. Optimal conditions for transfer of EAE will be investigated and whether this transfer of EAE could be abrogated by antigen specific suppressor T-cells will be studied. The overall goal of this proposal is to elucidate the immunological mechanisms involved in immunosuppression of EAE by BP complexed to LPS in rat model system.